Name
Configuration — Platform-specific Configuration Options
Overview
The phycore platform HAL package is loaded automatically when eCos is
configured for an phycore_lpc2294
target. It should
never be necessary to load this package explicitly. Unloading the
package should only happen as a side effect of switching target
hardware.
Startup
The phyCORE LPC229x platform HAL package supports two separate startup types:
- RAM
- This is the startup type which is normally used during application development. The board has RedBoot programmed into flash at location 0x0 in internal on-chip Flash and boots from that location. arm-eabi-gdb is then used to load a RAM startup application into memory and debug it. It is assumed that the hardware has already been initialized by the stubrom. By default the application will use the eCos virtual vectors mechanism to obtain certain services from the stubrom, including diagnostic output.
- ROM
- This startup type can be used for finished applications which will be programmed into internal flash at location 0x0. The application will be self-contained with no dependencies on services provided by other software. eCos startup code will perform all necessary hardware initialization.
RedBoot and Virtual Vectors
If the application is intended to act as a ROM monitor, providing
services for other applications, then the configuration option
CYGSEM_HAL_ROM_MONITOR
should be set. Typically
this option is set only when building RedBoot.
If the application is supposed to make use of services provided by a
ROM monitor, via the eCos virtual vector mechanism, then the
configuration option CYGSEM_HAL_USE_ROM_MONITOR
should be set. By default this option is enabled when building for a
RAM startup, disabled otherwise. It can be manually disabled for a RAM
startup, making the application self-contained, or as a testing step
before switching to ROM startup.
If the application does not rely on a ROM monitor for diagnostic services then serial port UART0 will be claimed for HAL diagnostics.
Flash Driver
The phyCORE LPC2294 board contains a number of AMD flash devices. The
CYGPKG_DEVS_FLASH_AMD_AM29XXXXX_V2
package contains
all the code necessary to support these parts and the
CYGPKG_DEVS_FLASH_ARM_PHYCORE
package contains
definitions that customize the driver to the phyCORE LPC2294 board.
Ethernet Driver
The phyCORE-LPC229x board contains an SMSC LAN91C111 ethernet MAC.
The CYGPKG_DEVS_ETH_SMSC_LAN91CXX
package contains all the code necessary to support this device and the
CYGPKG_DEVS_ETH_ARM_PHYCORE
package contains
definitions that customize the driver to the phyCORE LPC2294 board.
System Clock
By default, the system clock interrupts once every 10ms, corresponding
to a 100Hz clock. This can be changed by the configuration option
CYGNUM_HAL_RTC_DENOMINATOR
which corresponds to the
clock frequency. Other clock-related settings are recalculated
automatically if the denominator is changed. The PLL multipliers and
dividers may be configured to allow a core clock (CCLK) speed of up to
60MHz. The description of the clock-related CDL options may be found
in the LPC2xxx variant HAL documentation.
Memory Configuration
The PhyCORE LPC2294 board can be fitted with a wide range of flash and SRAM parts. The following options adjust the configuration of eCos and RedBoot to accommodate these variations:
-
CYGHWR_HAL_ARM_LPC2XXX_PHYCORE_MEMORY_CONFIGURATION_FLASH
- This option describes the flash devices fitted to the board. Possible values are: AM29DL800BT, AM29LV800BT, AM29LV160BT and AM29LV320BT. Of these only the AM29DL800BT and AM29LV320BT variants have been tested.
-
CYGHWR_HAL_ARM_LPC2XXX_PHYCORE_MEMORY_CONFIGURATION_FLASH_COUNT
- This option defines the number of flash devices fitted. Flash devices can only be fitted in pairs, and there is only space for up to 4, so this value can only be 2 or 4.
-
CYGHWR_HAL_ARM_LPC2XXX_PHYCORE_MEMORY_CONFIGURATION_SRAM_SIZE
- This option defines the total SRAM size. The board can be fitted with two or four SRAM devices, of 512KB, 1MB or 2MB each, giving Possible possible SRAM sizes of: 0x100000, 0x200000, 0x400000 or 0x800000.
Compiler Flags
The platform HAL defines the default compiler and linker flags for all packages, although it is possible to override these on a per-package basis. Most of the flags used are the same as for other architectures supported by eCos.
However there are two flags that are used if Thumb mode is to be supported:
-
-mthumb
- The arm-eabi-gcc compiler will compile C and C++ files into the Thumb instruction set when this option is used.
-
-mthumb-interwork
- This option allows programs to be created that mix ARM and Thumb instruction sets. Without this option, some memory can be saved. This option should be used if -mthumb is used.
2024-03-18 | eCosPro Non-Commercial Public License |